It's NOT an "end-consumer" device, like an Apple TV or a DVR or a microwave. By analogy
If you buy a car you expect it to come with door locks...
Yes, but you know the manufacturer does not provide those for free, which is why specific price tags are attached to specific goods. If I buy a car chassis, I may not expect locks. Of course, most people do not do this. But to reiterate "it's not an end-consumer device", it is not something most people would have any desire or interest in owning. Which "not most people" != "no one at all".
There's obviously some marketing philosophy going on. Like, for every feature that adds $1-2 to production costs, how is net sales going to be affected? Will we sell more because of the feature, or less because of the increased price? It is easy to say, "This will only add $0.50," but also easy to see there is a potentially very long list of things about which that might be said.
So what do the potential customers want to pay for, and what not? If there were a power button I guess that would be nice, but to be honest I could care less.
There's also a related issue, the more bells and whistles you add the more complex something is. This makes it more likely to break, in whole or part, and more difficult to debug when unforeseen problems arise.